Method of fabricating integrated circuit having staggered conductive features

ABSTRACT

A method includes using a processor to placing a cell having a first conductive feature and a second conductive feature on an integrated circuit layout. A length of the first conductive feature is extended, by using the processor, to form a staggered configuration. A set of instructions for manufacturing an integrated circuit based upon the integrated circuit layout is generated, and the set of instructions is stored in a non-transitory machine readable storage medium.

CROSS-REFERENCE TO RELATED APPLICATION

This is a Divisional Application of U.S. application Ser. No. 15/171,862, filed on Jun. 2, 2016, which is herein incorporated by reference in its entirety.

BACKGROUND

Computer-aided cell-based design has been developed for designing large scale ICs such as application specific integrated circuits (ASICs) and gate arrays. The cell is a circuit that has been pre-designed and pre-verified as a building block. In a standard cell design, each distinct cell in a library may have geometries of active, gate, and metal levels. Examples of a standard cell or gate array cell include an inverter, a NAND gate, a NOR gate, a flip flop, and other similar logic circuits.

Integrated circuit design includes two steps: placement and routing. During the placement step, the positions and orientations of cells are determined. During the routing step, interconnects or conductive features are added to connect ports on the cells.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1A to FIG. 1C respectively are schematic top views of different stages of a method of designing a cell layout having staggered conductive features in accordance with some embodiments of the present disclosure.

FIG. 2 is a schematic top view of a cell in accordance with some embodiments of the present disclosure.

FIG. 3A and FIG. 3B respectively are schematic top views of different stages of a method of designing a cell layout having staggered conductive features in accordance with some embodiments of the present disclosure.

FIG. 4A to FIG. 4C respectively are schematic top views of cell layouts in accordance with different embodiments of the present disclosure.

FIG. 5 is a schematic top view of an integrated circuit in accordance with some embodiments of the present disclosure.

FIG. 6 is a schematic top view of an integrated circuit in accordance with some other embodiments of the present disclosure.

FIG. 7A to FIG. 7C respectively are schematic views of different steps of a method of fabricating a cell in accordance with some embodiments of the present disclosure.

FIG. 8 is a processing system to generate one or more of the above described layout embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

Reference is made to FIG. 1A to FIG. 1C, which respectively are schematic top views of different stages of a method of designing a cell layout having staggered conductive features in accordance with some embodiments of the present disclosure. The designing method begins from FIG. 1A, in which a cell layout 100, such as a layout of a standard cell, is obtained from a cell library. The cell layout 100 has a boundary 110. The boundary 110 is substantially in a shape of rectangular. The boundary 110 includes a top edge 112, a bottom edge 114, and opposite side edges 116 and 118. A cell height H is defined between the top edge 112 and the bottom edge 114. (Note that while the top edge 112 of the boundary 110 is depicted facing upwards in the figures, rotating the cell layout 100 does not change the functions and relative positions of the elements shown. As depicted in the figures, the bottom edge 114 of the boundary 110 is shown oriented facing downwards; however, this does not change which portion is the bottom edge 114, even when the orientation is different.)

The cell layout 100 includes a plurality of standard conductive features 120 defined within the boundary 110. In some embodiments, the standard conductive features 120 are arranged substantially parallel to each other and are arranged substantially equally spaced apart. For example, FIG. 1A illustrates four standard conductive features 120 defined within the boundary 110 of the cell layout 100. In some other embodiments, the number of the standard conductive features 120 may vary according to different design requirements. A distance between adjacent standard conductive features 120 may be determined according to the design rule.

In some embodiments, the standard conductive features 120 have substantially the same length L1. The standard conductive features 120 may be aligned with each other. That is, the standard conductive features 120 are arranged at substantially the same level. As shown in FIG. 1A, top ends 122 of the standard conductive features 120 are aligned with a line LT, and bottom ends 124 of the standard conductive features 120 are aligned with a line LB.

In some embodiments, the standard conductive features 120 are for 5-pitch conductive feature routing, which refers to each of the standard conductive features 120 having five access points. The access point is a position where a conductive feature (e.g., a metal-2 line) can be connected to another conductive feature (e.g., a metal-1 line). The number of the access points plays a role to determine the routing ability, such as routing density and routing flexibility.

Reference is made to FIG. 1B. The standard conductive features 120 of FIG. 1A are shrunk and become shrunk standard conductive features 120′. As shown in FIG. 1B, the shrunk standard conductive features 120′ are shortened. Thus, a distance between the top edge 122 and the bottom edge 124 of at least one of the shrunk standard conductive features 120′ is smaller than a distance between the line LT and the line LB. The shrunk standard conductive features 120′ are present within a space between the line LT and the line LB. Therefore, some extra spaces are created by shrinking the standard conductive features 120 of FIG. 1A. In some embodiments, the shrunk standard conductive features 120′ still have substantially the same length L2, in which the length L2 of the shrunk standard conductive features 120 is smaller than the length L1 (as shown in FIG. 1A) of the standard conductive features 120 (as shown in FIG. 1A).

Reference is made to FIG. 1C. Upper extension portions 126 and lower extension portions 128 are respectively added to the shrunk standard conductive features 120′. In some embodiments, each of the shrunk standard conductive features 120′ is added with an extension portion, such as the upper extension portions 126 and the lower extension portions 128. As shown in FIG. 1C, the upper extension portions 126 are added to some of the shrunk standard conductive features 120′, and the lower extension portions 128 are added to the other shrunk standard conductive features 120′. The shrunk standard conductive features 120′ added with the lower extension portions 128 are referred to herein as first conductive features 130. The shrunk standard conductive features 120′ added with the upper extension portions 126 are referred to herein as second conductive features 140.

In some embodiments, the first conductive features 130 and second conductive features 140 have substantially the same length L3. The length L3 of the first conductive features 130 and second conductive features 140 can be similar to the length L1 of the standard conductive features 120 (as shown in FIG. 1A) or be longer than or shorter than the length L1 of the standard conductive features 120 (as shown in FIG. 1A). The length L3 of the first conductive features 130 and second conductive features 140 is smaller than the cell height H of the boundary 110.

In some embodiments, the first conductive feature 130 can be present closer to the bottom edge 114 of the boundary 110, and the second conductive feature 140 can be present closer to the top edge 112 of the boundary 110. That is, a first distance d1 from the top ends 132 of the first conductive features 130 to the top edge 112 of the boundary 110 is greater than a second distance d2 from the top ends 142 of the second conductive features 140 to the top edge 112 of the boundary 110. A third distance d3 from the bottom ends 134 of the first conductive features 130 to the bottom edge 114 of the boundary 110 is less than a fourth distance d4 from the bottom ends 144 of the second conductive features 140 to the bottom edge 114 of the boundary 110. In some embodiments, the first conductive feature 130 is protruded from the bottom end 144 of the second conductive feature 140 since the second conductive feature 140 is protruded from the top end 132 of the first conductive features 130. In some embodiments, both the top end 132 and the bottom end 134 of each first conductive feature 130 are located within the boundary 110, and both the top end 142 and the bottom end 144 of each second conductive feature 140 are located within the boundary 110.

Reference is made to both FIG. 1A and FIG. 1C. The first conductive features 130 and the second conductive features 140 are staggered, such that the capacity between the conductive features formed according a layout including the first conductive features 130 and the second conductive features 140 is smaller that between the conductive features formed according to the layout including the standard conductive features 120.

Referring to FIG. 2, which is a schematic top view of a cell in accordance with some embodiments of the present disclosure. The cell 200 is fabricated according to the cell layout 100 designed as discussed from FIG. 1A to FIG. 1C. The cell 200 includes a boundary 210, at least one first conductive feature 220, and at least one second conductive feature 230. The boundary 210 has a top edge 212, a bottom edge 214, and opposite side edges 216, 218.

The first conductive features 220 and the second conductive features 230 are arranged parallel to each other in the boundary 210, and the first conductive features 220 and the second conductive features 230 are staggered. In some embodiments, the first conductive features 220 and the second conductive features have substantially the same length. The first conductive features 220 and the second conductive features 230 are made of a conductive material. In some embodiments, the first conductive features 220 and the second conductive features 230 are made of metal, such as copper, tungsten, aluminum, or combinations thereof. The first conductive features 220 and the second conductive features 230 are linear-shaped.

In some embodiments, the first conductive features 220 and the second conductive features 230 are alternately arranged. Each of the first conductive features 220 is disposed between two of the second conductive features 230. Each of the second conductive features 230 is disposed between two of the first conductive features 220. The first conductive features 220 and the second conductive features 230 are staggered when viewed from the top. In some other embodiments, the sequence of the first conductive features 220 and the second conductive features 230 is not alternating.

In some embodiments, each of the first conductive features 220 has a first main portion 226 and a first extension portion 228, and each of the second conductive features 230 a second main portion 236 and a second extension portion 238. Ends (e.g. the top ends 222) of the first conductive features 220 have projections on the second conductive features 230, and the second extension portions 238 of the second conductive features 230 protrude from the projections of the ends of the first conductive features 220 on the second conductive features 230. Ends (e.g. the bottom ends 234) distal to the second extension portions 238 of the second conductive features 230 have projections on the first conductive feature 220 s, and the first extension portions 228 distal to the ends (e.g. the top ends 222) of the first conductive features 220 protrude from the projections of the ends of the second conductive features 230 on the first conductive features 220.

The number of the access points provided by the cell 200 can be increased by inducing the extension portions 228 and 238. For example, each of the first conductive features 220 may have five access points, and each of the second conductive features 230 may have five access points. Since the first conductive features 220 are arranged closer to the bottom edge 214, and the second conductive features 230 are arranged closer to the top edge 212 in the cell 200, the parts of the first conductive features 220 protruding from the second conductive features 230, such as the first extension portions 228, and the parts of the second conductive features 230 protruding from the first conductive features 220, such as the second extension portions 238. Such arrangement may increase the number of access points.

For example, each first main portion 226 may have four access points, and each first extension portion 228 may have one access point. Each second main portion 236 may have four access points, and each second extension portion 238 may have one access point. Therefore, the cell 200 provides six-pitch access points (e.g. including one access point provided by each first extension portion 228, four access points provided by each first (second) main portion 226 (236), and one access point provided by each second extension portion 238), which is more than the number of the access points of each first conductive feature 220 or each second conductive feature 230 itself.

Reference is made to FIG. 3A and FIG. 3B, which respectively are schematic top views of different stages of a method of designing a cell layout having staggered conductive features in accordance with some embodiments of the present disclosure. The method begins at FIG. 3A, in which a cell layout 300, such as a layout of a standard cell, is obtained from a cell library. The cell layout 300 has a boundary 310 and a plurality of standard conductive features 320 a-320 f present within the boundary 310. In some embodiments, the standard conductive features 320 a-320 f in the cell layout 300 may have different lengths respectively. For example, the standard conductive features 320 a may have a longest length among the standard conductive features 320 a-320 f, and the standard conductive feature 320 e may have a shortest length among the standard conductive features 320 a-320 f. In some embodiments, at least two of the standard conductive features 320 a-320 f, e.g. the standard conductive features 320 c and 320 f may have substantially the same length. In some embodiments, the standard conductive features 320 a-320 f are not aligned with each other, i.e. the standard conductive features 320 a-320 f are staggered arranged in the cell layout 300.

Referring to FIG. 3B, at least one extension portion 330 is added to at least one of the standard conductive features 320 according to a desired routing layout. The extension portions 330 are added to some of the standard conductive features 320 to provide additional access points at positions to where metal-2 lines are connected. For example, a top extension portion 330 a is added to the standard conductive feature 320 a, a bottom extension portion 330 b is added to the standard conductive feature 320 b, and a bottom extension portion 330 e is added to the standard conductive features 320 e. The length of each of the extension portions 330 can be the same or different. Since the length, the position, and the number of the extension portions 330 may vary according to the desired routing layout, the design flexibility and routing efficiency can be increased accordingly.

In some embodiment, the conductive features 340 a-340 f including the standard conductive features 320 a-320 f and the corresponding extension portions 330 a, 330 b, and 330 e are located within the boundary of the cell layout 300. The conductive features 340 a-340 f are arranged between the top edge 312 and the bottom edge 314 of the cell layout 300. In some embodiments, the conductive features 340 a-340 f are arranged parallel and are substantially equally spaced apart from each other. In some embodiments, the length of each of the conductive features 340 a-340 f can be different, and the conductive features 340 a-340 f are not aligned with each other. In some embodiments, the conductive features 340 a-340 f may be arranged in a staggered manner. Therefore, the capacitance present between the adjacent conductive features 340 a-340 f can be reduced accordingly.

Reference is made to FIG. 4A to FIG. 4C, which respectively are schematic top views of a cell layout in accordance with different embodiments of the present disclosure. For example, the cell layout 400 a includes six conductive features 421 a-426 a sequentially arranged in the boundary 410, as shown in FIG. 4A. In some embodiments, the conductive features 421 a-426 a have substantially the same length, and the conductive features 421 a-426 a are in a parallel arrangement. The conductive features 421 a-426 a may respective include a main portion 430 and a top extension portion 432 or a bottom extension portion 434. In some embodiments, the main portions 430 are arranged at the same level and have substantially the same length. The top extension portion 432 and the bottom extension portion 434 are selectively added to the corresponding main portions 430 according to the desired routing layout. As a result, some of the conductive features 421 a-426 a are protruded from others. For example, the conductive features 421 a and 424 a are present closer to the top edge 412 of the boundary 410, and top portions of the conductive features 421 a and 424 a are protruded from other conductive features (e.g. conductive features 422 a, 423 a, 425 a, and 426 a). Namely, the conductive features 422 a, 423 a, 425 a, and 426 a are present closer to the bottom edge 414 of the boundary 410, and the bottom portion of the conductive features 422 a, 423 a, 425 a, and 426 a are protruded from other (e.g. the conductive features 421 a and 424 a).

In some other embodiment, such as the cell layout 400 b in FIG. 4B, the cell layout 400 b includes six conductive features 421 b-426 b sequentially arranged in the boundary 410. In some embodiments, the cell layout 400 b is a standard cell obtained from a cell library, and the staggered conductive features 421 b-426 b are original conductive features in the cell layout 400 b.

In yet other embodiments, the conductive features are randomly arranged in the boundary, as shown in FIG. 4C. The cell layout 400 c may have six conductive features 421 c-426 c sequentially arranged in the boundary 410 in a parallel arrangement. The conductive features 421 c-426 c may have different lengths, and the conductive features 421 c-426 c may be arranged at different levels. In some embodiments, at least one of the conductive features 421 c-426 c extends across the edge of boundary 410. For example, the bottom portion of the conductive feature 424 c extends across the bottom edge 414 of the boundary 410, and the top portion of the conductive feature 425 c extends across the top edge 412 of the boundary 410. In some embodiments, the cell layout 400 c is a standard cell obtained from a cell library, and the staggered conductive features 421 c-426 c are original conductive features in the cell layout 400 c.

It is to be understood that the embodiments discusses from FIG. 4A to FIG. 4C are by examples, such that those skilled in the art can better understand the detailed description that follows. Those skilled in the art can readily use the present disclosure as a basis for designing or modifying other processes and structures. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

Reference is made to FIG. 5, which is a schematic top view of an integrated circuit in accordance with some embodiments of the present disclosure. The integrated circuit 500 includes a plurality of cells. For example, the integrated circuit 500 includes a first cell 510 and a second cell 550. The second cell 550 is abutted vertically on the first cell 510. In some embodiments, the first cell 510 and the second cell 550 have substantially the same layout.

The first cell 510 has a first boundary 520, a plurality of first conductive features 530, and a plurality of second conductive features 540. The first boundary 520 has a first top edge 522 and a first bottom edge 524 for defining a cell height therebetween. The first conductive features 530 and the second conductive features 540 are disposed in the first boundary 520. The first conductive features 530 and the second conductive features 540 have the same length. The first conductive features 530 are arranged closer to the first top edge 522 since the second conductive features 540 are arranged closer to the first bottom edge 524.

The second cell 550 includes a second boundary 560, a plurality of third conductive features 570, and a plurality of fourth conductive features 580. The second boundary 560 has a second top edge 562 and a second bottom edge 564 for defining the cell height there between. The second bottom edge 564 overlaps the first top edge 522. Namely, a common boundary between the first cell 510 and the second cell 550 can be regarded as both the second bottom edge 564 and the first top edge 522. The third conductive features 570 and the fourth conductive features 580 are disposed in the second boundary 560. The third conductive features 570 and the fourth conductive features 580 have the same length. The third conductive features 570 are arranged closer to the second top edge 562 since the fourth conductive features 580 are arranged closer to the second bottom edge 564.

The first conductive features 530, the second conductive features 540, the third conductive features 570, and the fourth conductive features 580 are in a shape of rectangular. The first conductive features 530, the second conductive features 540, the third conductive features 570, and the fourth conductive features 580 are in a parallel arrangement.

In some embodiments, the first conductive features 530 may extend across the first top edge 522, and the second conductive features 540 may extend across the first bottom edge 524. The third conductive features 570 may extend across the second top edge 562, and the fourth conductive features 580 may extend across the second bottom edge 564. The distance d3′ from the second bottom edge 564 to the bottom ends 574 of the third conductive features 570 is greater than the distance d1′ from the top ends 532 of the first conductive features 530 to the first top edge 522, such that the third conductive features 570 are spaced from the first conductive features 530. The distance d2′ from the top ends 542 of the second conductive features 540 to the first top edge 522 is greater than the distance d4′ from the second bottom edge 564 to the bottom ends 584 of the fourth conductive features 580, such that the second conductive features 540 are spaced from the fourth conductive features 580.

In some embodiments, the first conductive features 530, the second conductive features 540, the third conductive features 570, and the fourth conductive features 580 can be original conductive features from the standard cell stored in the cell library. In some other embodiments, the first conductive features 530, the second conductive features 540, the third conductive features 570, and the fourth conductive features 580 can include main portions and extension portions, in which the main portion can be standard conductive features from the standard cell or shrunk standard conductive features. The number, the ratio, and the arrangement of the first conductive features 530, the second conductive features 540, the third conductive features 570, and the fourth conductive features 580 may vary according to different design rules and different requirements.

Reference is made to FIG. 6, which is a schematic top view of an integrated circuit in accordance with some other embodiments of the present disclosure. The integrated circuit, such as the integrated circuit 500 as discussed in FIG. 5, further includes a plurality of lateral conductive features 600 a-600 c and conductive vias 610 a-610 d for interconnecting the lateral conductive features 600 a-600 d and the conductive features 530, 540, 570, and 580. The layout of the lateral conductive features 600 a-600 d and the conductive vias 610 a-610 d can be design by tools, such as by electronic design automation (EDA) tools. The first conductive features 530, the second conductive features 540, the third conductive features 570, and the fourth conductive features 580 are present in metal one lines. The lateral conductive features 600 a-600 d are present in metal two lines.

The lateral conductive feature 600 a is utilized to interconnect at least two of the second conductive features 540 at the extension portions of the second conductive features 540 (e.g. the portions of the second conductive features 540 protruding from the first conductive features 530). The extension portions of the second conductive features 540 and the lateral conductive features 600 a are cross at the conductive vias 610 a, and the conductive vias 610 a electrically connected the second conductive features 540 to the lateral conductive feature 600 a. In some embodiments, the lateral conductive features 600 b interconnects at least any two of the first conductive features 530 and the second conductive features 540, for example, the first conductive features 530 and the lateral conductive features 600 b are cross at the conductive vias 610 b, and the conductive vias 610 b electrically connected the first conductive features 530 to the lateral conductive feature 600 b. The lateral conductive feature 600 c is utilized to interconnect at least any two of the third conductive features 570 and the fourth conductive features 580, for example, one of the third conductive features 570 and the one of the fourth conductive features 580 are respectively cross the lateral conductive features 600 c at the conductive vias 610 c, and the conductive vias 610 c electrically connected the third conductive feature 570, the fourth conductive feature 580, and the lateral conductive feature 600 c. The lateral conductive feature 600 d is utilized to interconnect at least two of the third conductive features 570 at the extension portions of the third conductive features 570 (e.g. the portions of the third conductive features 570 protruding from the fourth conductive features 580). The extension portions of the third conductive features 570 and the lateral conductive features 600 d are cross at the conductive vias 610 d, and the conductive vias 610 d electrically connected the third conductive features 570 to the lateral conductive feature 600 d.

In some embodiments, the length of the protruding portions of the conductive features 530, 540, 570, 580 are greater than or equal to a pitch P between adjacent two of the lateral conductive features 600 a-600 d. The pitch P can be regarded as the minimum distance between wires of layers above the pin layer, such as the center line of 610 d and the center line of 610 c. In some embodiments, the pitch P is not greater than 64 nm. In some embodiments, the distance d5 between the bottom ends of the third conductive features 570 and the top ends of the second conductive features 540 is greater than or equal to a sum of the gap g between the first conductive features 530 and the third conductive features 570 and the pitch P between the conductive feature 600 d and conductive feature 600 e, e.g., d5≥(g+P).

However, the cell layouts of integrated circuit are only by examples, those skilled in the art can realize that other cell layouts, such as cell layouts discussed in FIG. 3A, FIG. 4A to FIG. 4C, or any other suitable cell layouts having staggered conductive feature arrangement, can be utilized in the integrated circuit for providing extra routing resources and improving routing flexibility.

Reference is made to FIG. 7A to FIG. 7C, in which FIG. 7A to FIG. 7C respectively are schematic views of different steps of a method of fabricating a cell in accordance with some embodiments of the present disclosure. Referring to FIG. 7A, a cell layout is provided. For easily understanding, the cell layout 700 is designed as described from FIG. 1A to FIG. 1C, for example. In some embodiments, two masks are utilized for fabricating the conductive features since the distance between the conductive features is tiny. For example, in FIG. 7B, a first mask is utilized for fabricating the odd rows (or the even rows) of the conductive features 710. After the odd rows (or the even rows) of conductive features 710 are formed, a second mask is utilized for fabricating the even rows (or the odd rows) of the conductive features 710, as shown in FIG. 7C.

Referring to FIG. 8, which is a processing system to generate one or more of the above described layout embodiments. Processing system 800 includes a processor 802, which may include a central processing unit, an input/output circuitry, a signal processing circuitry, and a volatile and/or a non-volatile memory. Processor 802 receives input, such as user input, from input device 804. The input device 804 may include one or more of a keyboard, a mouse, a tablet, a contact sensitive surface, a stylus, a microphone, and the like. The processor 802 may also receive input, such as standard cells, cell libraries, models, and the like, from a machine readable permanent storage medium 808. The machine readable permanent storage medium may be located locally to the processor 802, or may be remote from the processor 802, in which communications between the processor 802 and the machine readable permanent storage medium 808 occur over a network, such as a telephone network, the Internet, a local area network, wide area network, or the like. The machine readable permanent storage medium 808 may include one or more of a hard disk, magnetic storage, optical storage, non-volatile memory storage, and the like. Included in the machine readable permanent storage medium 808 may be database software for organizing data and instructions stored on the machine readable permanent storage medium 808. The processing system 800 may include an output device 806, such as one or more of a display device, speaker, and the like for outputting information to a user. As described above, the processor 802 generates a layout for an integrated circuit. The layout may be stored in the machine readable permanent storage medium 808. One or more integrated circuit manufacturing machines, such as a photomask generator 810 may communicate with the machine readable permanent storage medium 808, either locally or over a network, either directly or via an intermediate processor such as processor 802. In some embodiments, the photomask generator 810 generates one or more photomasks to be used in the manufacture of an integrated circuit, in conformance with a layout stored in the machine readable permanent storage medium 808.

The conductive features are not arranged at the same level in the cell, in which some of the conductive features have portions protruding from other conductive features, such that the access points of cell can be increased since the extension portions of the conductive features can be regarded as extra access points.

According to some embodiments of the present disclosure, a method includes using a processor to placing a cell having a first conductive feature and a second conductive feature on an integrated circuit layout. A length of the first conductive feature is extended, by using the processor, to form a staggered configuration. A set of instructions for manufacturing an integrated circuit based upon the integrated circuit layout is generated, and the set of instructions is stored in a non-transitory machine readable storage medium.

According to some embodiments, a method includes using a processor to place a cell having a first conductive feature and a second conductive feature on an integrated circuit layout. The lengths of the first conductive feature and the second conductive feature are shrunk, by using the processor. The first conductive feature is configure, by using the processor, such that a first edge of the first conductive feature is not aligned with a first edge of the second conductive feature. An integrated circuit based on the integrated circuit layout is fabricated.

According to some embodiments, a method includes using a processor to place a cell having a first conductive feature and a second conductive feature on an integrated circuit layout. The first conductive feature is configured, by using the processor, such that the first conductive feature is across a first edge of the cell. A set of instructions for manufacturing an integrated circuit based upon the integrated circuit layout is generated, and the set of instructions is stored in a non-transitory machine readable storage medium.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. 

What is claimed is:
 1. A method, comprising: using a processor, placing a cell having a first conductive feature and a second conductive feature on an integrated circuit layout; using the processor, extending a length of the first conductive feature to form a staggered configuration, wherein after extending the length of the first conductive feature, top and bottom of the first conductive feature are spaced apart from top and bottom of a boundary of the cell, respectively; generating a set of instructions for manufacturing an integrated circuit based upon the integrated circuit layout; and storing the set of instructions in a non-transitory machine readable storage medium.
 2. The method of claim 1, further comprising: using the processor, shrinking the length of the first conductive feature and a length of the second conductive feature prior to extending the length of the first conductive feature.
 3. The method of claim 2, wherein the length of the first conductive feature is substantially the same as the length of the second conductive feature after shrinking the length of the first conductive feature and the length of the second conductive feature.
 4. The method of claim 1, wherein extending the length of the first conductive feature is performed such that the length of the first conductive feature is extended in a first direction; and further comprising: extending the length of the second conductive feature in a second direction opposite the first direction.
 5. The method of claim 4, wherein the first conductive feature and the second conductive feature are adjacent to each other.
 6. The method of claim 4, wherein the length of the first conductive feature is substantially the same as the length of the second conductive feature after extending the length of the first conductive feature and extending the length of the second conductive feature.
 7. The method of claim 4, wherein extending the length of the second conductive feature is performed such that the second conductive feature is across the bottom of the cell.
 8. A method, comprising: using a processor, placing a cell having a first conductive feature and a second conductive feature on an integrated circuit layout; using the processor, shrinking lengths of the first conductive feature and the second conductive feature; using the processor, extending the length of the first conductive feature, such that a top of the first conductive feature is not aligned with a top of the second conductive feature and is spaced apart from a top of a boundary of the cell and such that a bottom of the first conductive feature is not aligned with a bottom of the second conductive feature and is spaced apart from a bottom of the boundary of the cell; and fabricating an integrated circuit based on the integrated circuit layout.
 9. The method of claim 8, wherein fabricating the integrated circuit comprising: fabricating, using a first mask, the first conductive feature; and fabricating, using a second mask, the second conductive feature.
 10. The method of claim 9, wherein the first conductive feature and the second conductive feature are adjacent to each other.
 11. The method of claim 8, wherein the top of the first conductive feature is substantially aligned with the top of the second conductive feature prior to extending the length of the first conductive feature.
 12. The method of claim 8, further comprising: configuring the second conductive feature, such that the bottom of the first conductive feature is not aligned with a bottom of the second conductive feature.
 13. The method of claim 12, wherein the bottom of the first conductive feature is substantially aligned with the bottom of the second conductive feature prior to configuring the second conductive feature.
 14. A method, comprising: using a processor, placing a cell having a first conductive feature and a second conductive feature on an integrated circuit layout; using the processor, extending a length of the first conductive feature, wherein extending the length of the first conductive feature is such that top and bottom of the first conductive feature are spaced apart from top and bottom of a boundary of the cell, respectively; and generating a set of instructions for manufacturing an integrated circuit based upon the integrated circuit layout; and storing the set of instructions in a non-transitory machine readable storage medium.
 15. The method of claim 14, further comprising: using the processor, configuring the second conductive feature, such that the second conductive feature is across the bottom of the boundary of the cell.
 16. The method of claim 15, further comprising: shrinking a length of the second conductive feature prior to configuring the second conductive feature.
 17. The method of claim 14, further comprising: shrinking a length of the first conductive feature prior to configuring the first conductive feature.
 18. The method of claim 8, wherein the length of the first conductive feature is substantially the same as the length of the second conductive feature after shrinking the length of the first conductive feature and the length of the second conductive feature.
 19. The method of claim 8, wherein the length of the first conductive feature is substantially the same as the length of the second conductive feature after extending the length of the first conductive feature and extending the length of the second conductive feature.
 20. The method of claim 8, wherein extending the length of the first conductive feature is performed such that the length of the first conductive feature is extended in a first direction; and further comprising: extending the length of the second conductive feature in a second direction opposite the first direction. 